title: Long-term cumulative depressive symptom burden and risk of cognitive decline and dementia among very old women.
abstract: BACKGROUND
  Depressive symptoms and cognitive outcomes are strongly interrelated. Despite that rates of depressive symptoms fluctuate during late life, little is known about the impact of long-term cumulative depressive symptom burden on cognitive decline and dementia in older adults. This study examines the association of nearly 20 years of cumulative depressive symptoms with cognitive outcomes in a cohort of older women.
  
  
  METHODS
  We assessed depressive symptoms in 7,240 women using the Geriatric Depression scale (GDS) at serial visits. We used a Poisson model with random slopes to estimate GDS trajectories for each participant from baseline to death or end of follow-up, and then characterized depressive symptom burden by quartile of the area under the curve. We assessed cognitive outcomes using repeated measures of the Mini-Mental State Examination (MMSE) and Trails B score over 20 years, Year-20 neuropsychological test battery, and adjudicated dementia and mild cognitive impairment (MCI).
  
  
  RESULTS
  Adjusting for potential confounders, compared with women in the lowest quartile of cumulative depressive symptoms burden, women in the highest quartile had 21% more MMSE errors over time (95% CI = 17%, 26%), 20% worse Trails B score over time (95% CI = 17%, 23%), worse scores on most of the Year-20 cognitive tests, and a twofold greater likelihood of developing dementia or MCI (95% CI = 1.48, 3.11).
  
  
  CONCLUSIONS
  Long-term cumulative depressive symptom burden was associated with cognitive decline and risk of dementia or MCI. Older adults with a history of depression should be closely monitored for recurrent episodes or unresolved depressive symptoms as well as any cognitive deficits.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Medicine, University of California San Francisco, 185 Berry Street, Lobby 5, Suite 5700, San Francisco, CA 94107. Adina.zekialhazzouri@ucsf.edu.
authors.forename: Adina
authors.initials: A
authors.lastname: Zeki Al Hazzouri
authors.forename: Eric
authors.initials: E
authors.lastname: Vittinghoff
authors.forename: Amy
authors.initials: A
authors.lastname: Byers
authors.forename: Ken
authors.initials: K
authors.lastname: Covinsky
authors.forename: Dan
authors.initials: D
authors.lastname: Blazer
authors.forename: Susan
authors.initials: S
authors.lastname: Diem
authors.forename: Kristine E
authors.initials: KE
authors.lastname: Ensrud
authors.forename: Kristine
authors.initials: K
authors.lastname: Yaffe
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000209:etiology*; D015331:Cohort Studies; D017281:Cost of Illness; D003704:Dementia / Q000209:etiology*; D003866:Depressive Disorder / Q000209:etiology* / Q000523:psychology*; D005260:Female; D006801:Humans; D012307:Risk Factors; D012737:Sex Factors; D013997:Time Factors
keywords: Alzheimer’s.; Cognition; Depression